This application claims the priority benefit of Taiwan application serial no. 90121109, filed Aug. 28, 2001.
1. Field of the Invention
The invention relates generally to circuit trimming and, more particularly, the invention relates to circuit trimming of a packaged IC chip.
2. Description of the Related Art
In integrated circuit (IC) manufactures, the final IC chip product generally does not run with exactly-expected results. These deviations are typically due to the accumulation of deviations of the numerous semiconductor processes that are performed to achieve the final IC chip product. In some cases, for example in digital circuits, the consequences of these deviations may be minor. In other cases when the input/output (I/O) signals of the IC chip product must be strictly controlled, for example in analog circuits, the consequences of these deviations may be problematic.
To compensate the deviations generated by the IC manufacture processes, circuit trimming is conventionally achieved via electrically coupling an adjuster device with the circuit of the IC chip.
Referring to FIG. 1, a block diagram schematically illustrates a conventional adjuster device for circuit trimming. As shown in FIG. 1, the output signal of an IC chip 100 conventionally pass through an adjuster device 102 before being externally delivered. The role of the adjuster device 102 is to ensure that the signal outputted by the IC chip 100 is strictly within a permitted range. To attain this purpose, the adjuster device 102 conventionally includes fuses (108, 110, 112) and resistors. Some of the fuses (108, 110, 112) may be electrically cut off to configure the adjuster device 102 in such a way that signals outputted are restricted within a desired range, thereby achieving circuit trimming of the IC chip 100.
With the adjuster device 102 coupled with the IC chip 100, configuring the adjuster device 102 may be typically accomplished either before or after the IC chip 100 is packaged. Before the IC chip 100 is packaged, the adjuster device 102 can be easily configured via, for example, a laser method that electrically cuts off the desired fuses. A disadvantage of this method is that it cannot compensate deviations due to IC chip packaging.
If circuit trimming is accomplished after the IC chip 100 is packaged, metal pads (103, 104, 106) and thereto-connected contact pins (not shown) must be conventionally arranged in such a manner that the contact pins externally expose through the packaging structure. Furthermore, an additional amount of circuitry is also necessary to enable the configuration of the adjuster circuit via the contact pins through the packaging structure. As a result, the space occupation of the adjuster circuit may be negatively increased, which results in an increase of the surface area of the IC chip. Because the number of contact pins is increased, accessibility problems may further arise
An aspect of the present invention is to provide a magnetically configurable adjuster device that, coupled with a packaged IC chip, can achieve circuit trimming without specific arrangements of additional contact pins and metal pads.
To accomplish the above and other objectives, the magnetically configurable adjuster device of the invention comprises a Hall element, a signal processor and amplifier device, a decoder, and a configurable adjuster. The signal processor and amplifier device connects to the output of the Hall element, the decoder connects to the output of the signal processor and amplifier device, and the configurable adjuster connects to the output of the decoder. The configurable adjuster includes a plurality of configurable elements and a plurality of circuit-trimming members, and further receives signals outputted by the packaged IC chip.
To achieve circuit trimming, a magnetic field is applied on the packaged IC chip. The magnetic field generated is directed to set a desired configuration of the configurable adjuster for achieving circuit trimming of the packaged IC chip. The Hall element senses and converts the magnetic field into a corresponding voltage signal by Hall effect. The voltage signal, after amplification through the signal processor and amplifier device, is delivered to the decoder. The decoder decodes the voltage signal into a plurality of decoded signals that are inputted to the configurable adjuster to configure the configurable elements. The configurable adjuster is thereby configured to obtain a desired circuit trimming of the packaged IC chip via the circuit-trimming members therein.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.